Gas wash solution heater for conveyorized washing machines



Sept. 17, 1963 R. K. NoLTE 3,103,936

GAS WASH SOLUTION HEATER FOR CONVEYORIZED WASHING MACHINES Filed Sept. 30.' 1960 2 Sheets-Sheet 1 ATTORNEYS v l u Sept. 17, 1963 R. K. NoL-rE n GAs wAsH- SOLUTION HEATER FoR WASHING MACHINES Filed sept. so. 1960 CONVEYORIZED 2 Sheets-Sheet 2 I INVENTOR POBERTA/Vorg ATTORNEYS 3,103,936 GAS WASH SLUTHN HEATER FOR CONVEYCR- LZED` WASHHNG MACHINES Robert K. Nolte, Chatham, NJ., assigner to Metalwash Machinery Company, Elizabeth, NJ., a co-partnership Filed Sept. 30, 1960, Ser. No. 59,767 3 Claims. (Cl. 134-72) This invention relates to conveyorized washing machines in general and in particular to a hot gas wash solution heater adapted to operate in a machine having a horizontal conveyor belt with a pitched drain plate therebelow.

Washing solution heaters of this general type have been .previously employed in industrial spray washers and are described in U.S. Letters Patent 2,841,136 assigned to the same assignee 1of the present invention, wherein a vertical hanging conveyor is used and where small amounts of foreign matter are removed by the washing solution. Due to the relatively light duty to which these washers were applied, no need forV straining of the spent wash water is necessary and the machines ordinarily do not contain a drain plate of any nature.

However, when continuous conveyorized washing machines are employed in applications such as the bakery pan cleaning iield, large amounts of foreign matter are removed from the pans and straining is necessary of all the spent washing solution prior to recirculation thereof. In order to separate the removed particles from the wash solution, a pitched drain plate is required -below the entire spraying chamber to direct the liquid to a strainer basket. If this type of straining were not required, the drain plate would not need to be 'included and the hot heating gases could be directed directly upward through the conveyor after passage through the solution tank heat exchanger. If this were the case, a conventional cover on the gas discharge pipe would prevent sprayed solution from entering the lire tube heat exchanger. However, because of the presence of the drain pan covering the wash water tank, no direct flow of hot gas is possible between the tank water heat exchanger and the spray chamber.

Accordingly, the present invention adapts a re tube heat exchanger disposed within a washing solution tank having a pitched drain pan thereover to also heat the liquid sprays about the horizontal conveyor. The invention channels the hot gas products of combustion leaving the heat exchanger, upwardly, around the drain pan and directs these gases through the water spraying chamber along the path of the conveyor belt to accomplish a second stage heat transfer to the washing stream prior to venting through a ue. The routing of the hot gas through the liquid, in the tank portion of the invention, is in an S-shaped piping arrangement, which, due to the large spacing between turns, will not collect any residual waste which would hinder maximum heat transfer to the liquid. The gas exiting from the tank heat exchanger is ducted upwardly and enters the top portion of the washing chamber above the level of the liquid spray and is directed downwardly, by baies, so that the hot gas will be projected into the spraying area above the conveyor path. In this way, none of the sprayed liquid will enter the hot `gas discharge opening and no protective cover is required over the opening to prevent entry of sprayed liquid into the tire tube heat exchanger and hot gas generation means.

An object of the invention therefore is to provide a two-stage hot gas water heater to a washing machine having a horizontal conveyor.

A further object is to provide a heating device for washing solutions which is highly eflicient and exhausts relatively low temperature ue gases.

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Patented Sept. 17, 1963 Another object is to provide a combination article washing and liquid heating device.

Another object of the invention is to provide an improved etliciency serpentine path tire tube heat exchanger which is not susceptible to clogging by washed-off particles suspended in the washing solution.

Yet another object of the invention is to provide a horizontal conveyorized washing machine having a hot gas heat exchanger adapted to exhaust above the washing solution level at substantially the level of the sprayed solution.

Yet another object of the invention is to provide a twostage washing solution heating device which is simple in design, durable in construction and economical to manufacture.

Other objects and advantages of the invention will become apparent and the invention will be fully understood from the following description and drawings in which:

FIG. 1 is a horizontal section taken on the line 1--1 of FIG. 2 of a combined conveyorized washer and solution heater constructed in accordance with the invention;

FIG. 2 is a vertical cross section taken on the line 2 2 of FIG. 1 and FIG. 3 is a cross section view taken on the line 3-3 of FIG. 1.

Referring to the drawings in particular, the invention as embodied therein includes a plurality rof liquid reservoirs two of which, 10 and 12, are indicated in the drawings arranged side by side and separated by a dividing wall 13. Above reservoirs 10 and 12 are substantially rectangular spray chamber tanks 14 and 16, respectively.

The reservoir tanks 1t) and 12 and the liquid spray tanks 14 and 16 are of a length and number to correspond to the size of an endless horizontal conveyor 18 which is arranged to move throughout the length of the adjacent spray chamber tanks 14 and 16 and additional tanks (not shown) as required. Articles, s-uch as baking pans, to be cleaned are normally placed on the conveyor :18 through an opening 20` in an end wall, and are transported on the conveyor along a path located between downwardly and upwardly directed sprays of liquid directed from upper and lower sets of pipes 22 and 23 by means `of pumps 25 arranged -to recirculate the solution vin reservoirs 1t) and 12. The pipes 22 vand 23 extend across the spray chambers 14 and 16 aboveand below the top belt portion of the conveyor 18. The conveyor is preferably made of wire mesh material so that liquid and foreign matter will readily pass therethrough. Horizontally separating each tank 10 and :12 from its respective spray chamber 14 and 16 is a pitched drain plate 17 which catches the spent sprayed solution and foreign matter Iand directs it through an opening 19 into a strainer basket 2.1 located within the tanks. Screened solution is then strained from tanks 10 and 12 through inlet screens l23 in front of pumps 25 recirculated through the pipes 22 and 23.

In accordance with the invention a combustion device such as an oil burner or gas jet 24 is located in an end wall 26 of each of the reservoir tanks 10 and .12 and arranged to direot high temperature combustion gases through substantially cylindrical S-shaped heat exchangers 2SA and 30. Each of the conduits 28 and 30 is S-shaped to conduct the gases through an extended path within the solution tank and then upwardly through upstanding riser portions 36 and 38 which exit through openings 40 and 42, respectively, into each ofthe spray chambers 14 and 16. I-nclned bales 44 and 46 are provided adjacent each of the openings 40 and 42, re-

spectively, in order to direct the gases through chambers 14 and 16. Addi-tional baffles, such as vertical batlies 43, are provided :to lower the flow path of the hot gases and insure that they pass through the spray produced by the liquid exiting from the conduits 22 and 23 and insure that this liquid is further heated. The gases are lthen drawn off by means of blowers 48, 4S arranged at opposite ends of the chambers 14, 16.

In operation, the hot products of combustion pass through fthe SShaped heat exchangers 28` and 3h submerged within the washing solution and exit therefrom into upstanding riser portions 36 and 3S to by-pass the inclined drain plate 17. The gases emerging from the rupper portion of the risers 36 and 38 are directed back into the spray chambers through openings 4) and 42, substantially above and separated from the liquid sprays. The baffles 43 are provided to redirect the gas discharge into a lower strata so that a secondary heating of the water liquid will occur in the spray chamber prior to venting through the blowers 48. In this way, by ernploying vertical riser portions which discharge the hot gas at a position substantially above and separated from the spray chambers, a complete drainage plate 17 may be employed under the entire spray area without the possibility of sprayed liquid entering the hot gas discharge vents 40 and 42.

Thus, the invention provides means for transporting articles on a horizontal conveyor through one or more tanks ywhich include liquid sprays directed at the articles being transported and a pitched drainage plate completely below the spray areas. The invention further provides means for heating the washing solution with a heat exchanger submerged within the reservoir tank and also heating the liquid sprays with the hot gas discharged from the submerged heat exchanger without the need for any elaborate cover or door arrangement at the heat exchanger discharge opening to prevent entry of spray into the heat exchanger.

While a specific embodiment of the invention has been shown and described in detail to illustrate the application of the invention principles, it will be understood that the invention may be embodied otherwise without departing from such principles.

What is claimed is:

1. `ln an article washer of the type having a liquid reservoir tank, a spray chamber arranged above said reservoir tank, means for conveying articles through said spray chamber, liquid spray means arranged to direct liquid onto articles transported by said conveyor means and inclined drainage means extending horizontally between said spray means and said reservoir tank, and means to pass high temperature gases through said reservoir tank, the improvement comprising a vertical duct portion connecting to said last mentioned means, adapted to receive said high temperature gases and routing same upwardly from said reservoir tank exterior of said inclined drainage means, and outlet means at the upper end of said duct portion disposed at a level above the level of said drainage means, said outlet means being removed from the spray in said spray chamber and adapted to emit said high temperature gases to accomplish a direct contact secondary heating of the liquid emitted from said spray means substantially before its contact with :the articles to be washed thereby substantially avoiding heating of the spent liquid.

2. In a device according to claim l, the improvement further including means for directing the high temperature gases emitted by said outlet means into the interior of the spray chamber and into direct contact with said liquid spray to accomplish a concentrated secondary heating thereof.

3. A combination anticle washer and liquid heater comprising an elongated substantially rectangular reservoir tank, heating tube means in said reservoir tank extending backwardly and forwardly along the length thereof and then upwardly, wall means dening a spray chamber above said reservoir tank in communication with said heating tube means, an endless belt conveyor arranged to extend through said spray chamber, means to spray liquid in the vicinity of said conveyor, inclined plate means extending horizontally below said conveyor separating said spray chamber and said reservoir tank, means to direct high temperature heating gases through said heating tube means in said reservoir tank and then upwardly exteriorly of said plate means into said spray chamber at a discharge level above said plate means and 4vertical baille means afxed to a Wall of said spray chamber Ato prevent entry of sprayed liquid into said tube means and to introduce the high-temperature heating gases into direct contact with the sprayed liquid at a level above said conveyor for a concentrated secondary heating thereof Without the unnecessary heating of the spent washing liquid below said conveyor.

References Cited in the le of this patent UNITED STATES PATENTS 1,335,853 Myrick Apr. 6, 1920 1,899,657 Zademach Feb. 28, `1933 2,721,564 Kearney Oct. 24, 1955 2,841,136 Pettit et al. July 1, 1958 3,023,757 MiXon Mar. 6, 1962 FOREIGN PATENTS 243,875 Great Britain Dec. 10, 1925 

1. IN AN ARTICLE WASHER OF THE TYPE HAVING A LIQUID RESERVOIR TANK, A SPRAY CHAMBER ARRANGED ABOVE SAID RESERVOIR TANK, MEANS FOR CONVEYING ARTICLES THROUGH SAID SPRAY CHAMBER, LIQUID SPRAY MEANS ARRANGED TO DIRECT LIQUID ONTO ARTICLES TRANSPORTED BY SAID CONVEYOR MEANS AND INCLINED DRAINAGE MEANS EXTENDING HORIZONTALLY BETWEEN SAID SPRAY MEANS AND SAID RESERVOIR TANK, AND MEANS TO PASS HIGH TEMPERATURE GASES THROUGH SAID RESERVOIR TANK, THE IMPROVEMENT COMPRISING A VERTICAL DUCT PORTION CONNECTING TO SAID LAST MENTIONED MEANS, ADAPTED TO RECEIVE SAID HIGH TEMPERATURE GASES AND ROUTING SAME UPWARDLY FROM SAID RESERVOIR TANK EXTERIOR OF SAID INCLINED DRAINAGE MEANS, AND OUTLET MEANS AT THE UPPER END OF SAID DUCT PORTION DISPOSED AT A LEVEL ABOVE THE LEVEL OF SAID DRAINAGE MEANS, SAID OUTLET MEANS BEING REMOVED FROM THE SPRAY IN SAID SPRAY CHAMBER AND ADAPTED TO EMIT SAID HIGH TEMPERATURE GASES TO ACCOMPLISH A DIRECT CONTACT SECONDARY HEATING OF THE LIQUID EMITTED FROM SAID SPRAY MEANS SUBSTANTIALLY BEFORE ITS CONTACT WITH THE ARTICLES TO BE WASHED THEREBY SUBSTANTIALLY AVOIDING HEATING OF THE SPENT LIQUID. 